A troll is someone that makes posts with the intent to piss everyone off. Considering most trolls get that effect by some method or another, I'd say the worst troll would be someone that manages to upset everyone without the intent of making people angry. That gives us a wide variety of choices, as we all manage to agitate others at times.
Lucy can count I just think she's a forum troll. Bcuz its her threads. Its like if none are active make more. Worst troll really deps on the ppl tbh you could make a list.